Safety goggles are used in many industries and trades to protect a workers eyes. When workers are welding, cutting with a torch, or the like, goggles are used not only to protect the eyes from accidents resulting from particles getting into the eye, but also to protect the eyes from high intensity light emitted in the process. These types of goggles, which can be referred to generally as welders goggles, comprise of a filter plate, and usually a protective cover plate, through which the wearer views, both held in an opaque goggle body. The filter plate acts to shield the eyes from the intense light and flying particles, and the cover plate acts to protect the filter plate from flying particles.
The goggle body is generally made of an opaque pliable plastic so as to conform closely to the contour of the face. The close fit helps to assure that particles do not enter from the sides. The conforming fit also combines with the opaqueness to help assure that unfiltered light does not enter the interior of the goggle when worm. Unfiltered light entering the interior of the goggle during use, causes reflections from the rear surface of the filter plate which reduces or confuses the vision of the wearer.
Ventilation of the interior of the goggle is desireable, and almost essential, in a commercially acceptable goggle in order to allow moisture to evaporate from the interior. The moisture in the interior is caused primarily by perspiration of the skin enclosed by the goggles, and by ventilating the interior, the goggles are more confortable for the wearer. But more importantly, the ventilation reduces the tendency of the goggles to "fog up."
In the past "stack vents" were used for ventilation. These vents are well known to those skilled in the art, and essentially comprise an opening in the goggle body, generally located at the sides of the body, and covered by a cap. The shape of the cap and the opening combine to provide air passages, but yet not provide a straightline path through which projected particles or light could pass. These stack vents do provide some measure of ventilation, but they are fairly expensive, and prior art goggles utilizing stack vents have a ventilating ability which is somewhat less than desireable.
The present invention provides a goggle which has improved ventilation, and which is less expensive to manufacture. The goggle generally comprises a goggle body, a plate holder or cartridge and a filter plate assembly. The filter plate assembly is retained in the cartridge and the cartridge is positioned in a viewing aperture in the front of the goggle body. A plurality of ventilating holes are formed along the top and bottom of the goggle body and along the top and bottom of the cartridge. When the goggle is assembled, the holes in the goggle body and the holes in the cartridge are displaced from each other. A plurality of tabs are interposed between the holes in the body and the holes in the cartridge so as to form non-straight-line or non-line-of-sight air flow paths between the holes in the body and the holes in the cartridge, thus, providing ventilation without the admission of objectionable light to the interior of the goggle.
The holes in the cartridge are located to be open to the interior of the goggle just behind the filter plate assembly. When worn, the air in the interior of the goggle is heated by the skin enclosed by the goggle. This heated air rises and passes out of the top holes, thus drawing cooler dry air in through the bottom holes. And, because of the location of the ventilating holes in the cartridge, the air drawn in at the bottom follows a flow path in close proximity to the interior surface of the filter plate assembly. This air flow across the interior surface of the filter plate assembly results in a reduced tendency of the filter plate to fog up.